Present day telecommunications networks typically include a plurality of switching systems linked via transmission facilities (e.g., trunks and/or channels) that carry "calls" (in the form of voice, video or data) between switching systems. Additionally, these switching systems are typically linked via a signaling (data) network that transmits signaling messages between switching systems. Further, within a given telecommunications network, control information may flow between switching systems and databases, intelligent peripherals, or other specialized resources, as is well known in the art. For the purposes of this invention these databases, intelligent peripherals, or other specialized resources are deemed as the associated telecommunications network infrastructure.
A present day switching system consists of a switching fabric and a control mechanism as a single integrated system. The control mechanism of a switching system provides the intelligence to operate a specific switching fabric and some (or possibly all) of the intelligence to interpret and respond to signals. The switching fabric includes devices for the termination of transmission facilities, as well as devices which provide multiple stages of space and time switching as is understood in the art. Additionally, the switching fabric may also include local intelligence, in the form of a processor or the like, for acting upon commands from the control mechanism. Within prior art switching systems the control mechanism is typically provided by special purpose computers. The basic functions performed by switching systems include connecting communications paths, and to varying degrees, receiving and sending signaling messages, performing operations, administration and maintenance functions, and providing call processing and customer services (e.g., service logic). In the context of this disclosure, the phrase connection functions includes functions such as: receiving dialed digits, determining whether a call can be established, reserving a communication channel, setting up and maintaining the channel, taking down the channel, reserving bandwidth and modifying a resource.
Present day telecommunication networks are typically adapted for specific applications, such as voice, video, or data. These networks differ from one another in various respects, for example, in the transmission method (e.g., circuit, wireless, and packet which should be considered inclusive of various packet methods including packet, cell, and frame relay), used by a call to access the telecommunications network. Further each network typically is comprised of specialized signaling protocols, databases, and transmission facilities. In addition, adding a new application to a present day telecommunications network (for example, adding video capability to a voice telecommunications network) typically requires development of entirely new call processing, signaling, and operational functionality. Moreover, since much of the hardware and software functionality of present day switching systems is dependent on the specific application, it is difficult to add new functionality without massive re-working of the software within the switch.
As the demand for new and enhanced telecommunication services proliferates, there is a need for a telecommunications network architecture that affords greater flexibility at a reduced cost by allowing re-use of existing switching systems and their associated telecommunications network infrastructure.